Layers and layer management have been expanded greatly in WF and WF2, including adding secret, hidden layers, such as .BLACK_HOLE. Modelcheck will turn up this layer. It makes things like the old unseen 'datum-on-the-fly'. The new Pro/e find function may turn it up, but what you can do with it after that is not much more than see if it clicks somewhere. The nice thing about this new Find is that it seems to be context aware, i.e., if you are in a function where selection is necessary, Find may give you options you didn't have before. And if you find something applicable, Apply may get it where it will do some good.